Device, system and method for implantation of filaments and particles in the body

ABSTRACT

A method of introducing continuous lengths of filament into the body in surgical procedures in which it is desirable to place a significant amount of material into the body through a small portal. The material so introduced may serve to bulk a tissue or cavity of the body or to occlude a vas, as well as to introduce diagnostic or therapeutic agents into a site in the body. A device for implementing the method has a mechanism for feeding the filament through a conduit in such a manner that sufficient force is applied to the filament that it is forced into the desired site. In one embodiment, a system of reciprocating cannulae and synchronized grippers is used to supply the requisite force to the filament.

TECHNICAL FIELD

[0001] The present invention relates to a device and method fortherapeutic insertion of suture and other materials into body tissue infilamentous and particulate form.

BACKGROUND OF THE INVENTION

[0002] Increasingly in medicine and surgery, the need arises to place amass of material either into body tissue or into a space in the bodyproximate to body tissue for various clinical purposes. These purposesinclude the bulking of tissue as a therapy for intrinsic sphinctericdeficiency (ISD) which gives rise to incontinence. In some types ofincontinence, a decrease in urethral resistance leads to urinary leakageduring stress. This leakage is embarrassing, and may cause the person tochange their life-style to avoid activity. Recently, various injectablematerials have been suggested for the purpose of ‘bulking’ theperiurethral space, coapting the urethra, and thus increasing theurethral resistance.

[0003] Other clinical applications include the implantation of materialinclude the occlusion of aneurysms, arteriovenous malformations (AVMs),and fistulas, as well as the occlusion of the blood supply to tumors,especially cranial tumors, prior to surgery to reduce bleeding duringsurgery.

[0004] To insure that such procedures are minimally invasive, it wasclinically determined that bulking, for example, should be accomplishedthrough needle injection. Due to the use of a needle, it was believedthat it was necessary to reduce the material to a liquid suspension orparticulate so that it might be capable of being passed through a needleinto the tissue. This reduced the number of candidate materialssignificantly. Teflon (PTFE) particles, silicone particles, collagensuspensions, and various other materials were tried. Most of theproblems associated with the therapy were associated with the material.For example, collagen resorbed too quickly, creating the need for manyrepeat therapies. Teflon particles migrate through the body and are thusclinically undesirable.

[0005] Known technology has similarly limited the materials which can bedelivered transvascularly, endoscopically, or via a conduit inconjunction with a laparoscope. Articles that are delivered by pushingand utilization of these devices are limited, typically, either tofluids or to relatively stiff solids.

[0006] The controlled release of drugs from polymer and from surgicalsuture is another therapeutic modality known in the art. Application ofthis technique, however, has hitherto required the insertion of sutureusing conventional methods of pulling the suture into the tissue, as bymeans of a sewing needle or tweezers, raising difficulties of access tothe site of implantation.

SUMMARY OF THE INVENTION

[0007] The present invention expands the domain of materials that may beused for bulking as well as for other cellular and drug deliveryapplications. The invention allows for a filament, as defined below, tobe introduced through a needle or other conduit, allowing suchwell-known biocompatible materials as those used in suture to beconsidered. With this novel advance, not only can the material have abulking effect, but depending on the other properties of the filamentused, it may add other mechanical attributes such as springiness,rigidity, flexibility, mass, orientation, and permeability. Further, thematerial being introduced may be a solid, compressed particulate orcomposite, thereby opening up a range of possible functions the materialmay perform such as drug delivery, radiation, chemotherapy orthermotherapy. The three-dimensional nature of the end result may bevery appropriate to provide a scaffolding for cellular ingrowth forcells either injected with the filament, or those induced to grow intothe matrix.

[0008] The device is capable of placing a significant amount of materialin the body through a small portal, i.e., an opening in the body asdefined below. This material may preloaded with a drug, or cells, orsome other active material to produce some desired effect with the body.The dosage may be controlled by the length of the filament and thenature of the preloading, and may be modified at the time of delivery tothe length of choice. Such a method may be useful for the delivery ofsubcutaneous heparin, insulin, contraceptive substances, and otherpharmaceuticals useful for heart disease, smoking cessation, etc. Theadvantage of this approach over other subcutaneous drug delivery devicesis its extremely low profile, and the ease in which it is positionedwithin any site in the body, in particular, in the proximity of thetissue to be affected.

[0009] In accordance with a preferred embodiment of the invention, amethod is provided for modifying a tissue property of a subject, whereinthe method consists of providing a quantity of filament, opening aportal in the body of the subject, where both “filament” and “portal”are defined below, inserting the filament through the portal into aregion in the vicinity of the tissue, and localizing the filament in theregion so as to modify the tissue property. The tissue property to bemodified may include the mass, bulk, orientation, rigidity, flexibility,springiness, and permeability of the tissue. The filament is inserteddirectly, or with the aid of an endoscope or a laparoscope. Embodimentsof the invention provide methods for bulking the tissue of a subject,coapting the walls of a vas, where “vas” is defined below, occluding avas, preventing pregnancy, sterilizing a subject, clotting an ulcer,treating an aortic aneurism, treating a bleeding esophageal varix,providing chemotherapy, releasing a drug, catalyzing biochemicalreactions, providing birth control, supporting cell growth in a subject,sewing body tissue, delivering anesthesia, and delivering a stent into avas. Each of the aforesaid methods has the steps of providing a quantityof filament and inserting it into the body. The filament may bepreloaded as described above. In further embodiments of the invention, acontinuous length of filament may be severed to provide a desired lengthof filament within the body of the subject, and fluid may also beinjected into the subject in conjunction with the filament.Additionally, in accordance with an alternate embodiment of theinvention, suture is provided in particulate form, suspended in a liquidcarrier to create a suture suspension, and inserted through a portal inthe body of a subject to modify a tissue property that includes at leastone of the mass, bulk, orientation, rigidity, flexibility, springiness,and permeability of the tissue.

[0010] In another embodiment of the invention, a method is provided forremoving filament from a site in the body that consists of the steps ofinserting a hollow shaft into the site, hooking the filament with ahooked tool, and withdrawing the filament via the hollow shaft.

[0011] In accordance with another aspect of the invention, a device isprovided that has a conduit for insertion into a designated site in thebody, and a feeding mechanism for supplying filament along the axis ofthe conduit in a manner such that support is provided across all lengthsof the filament longer than three times the diameter of the filament.The conduit may be rigid, as well as semi-rigid or flexible.

[0012] In one embodiment of the invention, the feeding mechanism has aninner cannula with an inner diameter corresponding generally to thediameter of the filament and a mounting arrangement, which may be acoaxial outer cannula, for permitting the axial movement of the innercannula. Finally, an actuator mechanism is provided for urging the innercannula in axial reciprocation consisting of forward motion andretrograde motion with respect to the mounting arrangement. In alternateembodiments, the actuator mechanism may have a combination of grippersor a gripper and a brake. Additionally, the inner cannula may havedistinct proximal and distal segments and a containment spring forretracting the distal segment toward the proximal segment duringretrograde motion of the distal segment.

[0013] In further embodiments of the present invention, a tip may beprovided on the mounting arrangement for penetrating body tissue, and awindow may be provided proximally to the tip to allow filament to be fedinto the site. Filament cutters are provided in several alternateembodiments to allow desired lengths of filament to be left in the body.In one filament cutter embodiment, a torquable head is disposed adjacentto the distal end of the conduit with a shearing surface disposed on atleast one of the torquable head and the distal end of the conduit suchthat rotation of the torquable head severs the filament. In anotherfilament cutter embodiment, a shearing surface is provided on at leastone of the inner cannula and mounting arrangement of the device suchthat relative motion of the inner cannula and mounting arrangement causeshearing of the filament.

[0014] Other filament feeding mechanisms are provided in alternateembodiments of the invention which include conveyor belts engagedagainst the filament, a toothed wheel and idler wheel for advancing thefilament, and a reciprocating shaft which drives the filament forward inthe shaft and then springs back in disengagement from the filament. Amotor may be employed for repetitively cycling the feeding mechanism.

[0015] In accordance with another aspect of the present invention, adevice is provided for removing a filament from a site in the body wherethe device consists of a conduit and a hook for snagging and withdrawingthe filament through the conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a schematic illustration of a filament injection device1 in accordance with a preferred embodiment of the present invention.

[0017]FIG. 2 illustrates the principal components of a filamentinjection device in accordance with a preferred embodiment of thepresent invention.

[0018] FIGS. 3A-3C show cross-sectional views of a filament feedingmechanism in the advancement stage of a filament feeding cycle inaccordance with the embodiment of the invention shown in FIG. 2.

[0019]FIGS. 4A and 4B show cross-sectional views of a filament feedingmechanism in a the reset stage of a filament feeding cycle in accordancewith the embodiment of the invention shown in FIG. 2.

[0020]FIG. 5 shows an exploded view of a filament feeding mechanismaccording to an embodiment of the invention.

[0021]FIG. 6 is a cross-sectional view of the distal tip of a filamentfeeding mechanism in accordance with an embodiment, of the invention.

[0022]FIGS. 7A and 7B are cross-sectional views of the distal tip ofFIG. 6, showing a filament cutting mechanism according to an embodimentof the invention.

[0023]FIG. 7C is a perspective view of the distal tip of a conduit inaccordance with an embodiment of the invention showing an alternatefilament cutting mechanism.

[0024]FIG. 7D is a cross-sectional view of the filament cuttingmechanism of FIG. 7C.

[0025]FIG. 8 is a cross-sectional view of an filament feeding mechanismaccording to an alternate embodiment of the invention.

[0026]FIG. 9 is a schematic of a powered drive system for cycling theshaft 27 with the touch of a button.

[0027]FIG. 10 illustrates a layout of an alternative embodiment of thesystem.

[0028]FIG. 11A is a cross section of the result after the device hasbeen used to coapt the walls of a tubular structure within the body.

[0029]FIG. 11B illustrates an embodiment of the invention for treatmentof an ulcer.

[0030]FIG. 12 illustrates an embodiment of the invention for removing afilament in the body after it has been placed.

[0031] FIGS. 13A-13C illustrate use of the device of FIG. 1 for passingsuture through and around tissue, and, in FIG. 13C, for creating aseries of linked loops.

[0032]FIG. 14 illustrates the mechanism through which particle may beinjected into the body in accordance with another embodiment of theinvention.

[0033]FIGS. 15A and 15B show respectively a descended bladder of afemale subject and the same bladder after it has been elevated by use ofa filament implanted in accordance with an embodiment of the invention;

[0034]FIG. 16 shows an embolism that has been achieved in a blood vesselby means of a filament implanted in accordance with an embodiment of theinvention;

[0035]FIG. 17 shows an aneurysm that has been filled by means of afilament implanted in accordance with an embodiment of the invention.

[0036]FIGS. 18 through 26 illustrate various embodiments of theinvention for achieving the movement of a filament along a desired pathso as to permit implantation of the filament;

[0037]FIGS. 18A and 18B illustrate an embodiment for achieving movementof a filament utilizing a pair of conveyor belts symmetrically engagedagainst the filament;

[0038]FIG. 19 illustrates an embodiment for achieving movement of afilament utilizing a toothed drive wheel against which the filament isengaged by an idler wheel;

[0039]FIG. 20 illustrates an embodiment, similar to that of FIG. 19,utilizing a toothed drive wheel against which the filament is engaged byan idler wheel, but wherein the filament is also engaged against thedrive wheel by a guide having an arcuate surface that general conformsto the radius of the drive wheel;

[0040]FIGS. 21A and 21B illustrate and embodiment, similar to that ofFIG. 19, utilizing a toothed drive wheel against which the filament isengaged by an idler wheel, but wherein the idler wheel is soft;

[0041]FIG. 22 illustrates an embodiment for achieving movement of afilament utilizing a toothed drive wheel against which the filament isengaged by a tubular guide;

[0042]FIGS. 23A and 23B illustrate an embodiment for achieving movementof a filament utilizing a drive wheel against which the filament isengaged by an idler belt;

[0043]FIGS. 24A through 24E illustrate an embodiment for achievingmovement of a filament utilizing a pair of axially reciprocating tubularmembers, within which the filament is disposed, in conjunction with aperiodically clamping finger;

[0044]FIGS. 25A through 25E illustrate an embodiment similar to that ofFIGS. 24A through 24E but in which the coil springs of the latterfigures are supplanted by complementary mating extensions of the tubularmembers;

[0045]FIGS. 26A and 26B illustrate an embodiment for achieving movementof a filament utilizing a pair of arms that are caused to reciprocateaxially while being alternately opened and closed at the opposite endsof each stroke;

[0046]FIGS. 27A through 3 ID illustrate embodiments of the invention inwhich a region proximate to a tip of a cannula carrying a filament isprovided with an arrangement, for cutting the filament, utilizing aconcentrically disposed member and a window in both members throughwhich the filament is placed and severed;

[0047]FIGS. 27A and 27B illustrate an embodiment wherein the outermember is pulled proximally with respect to the inner member to achievecutting;

[0048]FIGS. 28A and 28B illustrate an embodiment wherein the outermember is pushed distally with respect to the inner member to achievecutting;

[0049]FIGS. 29A through 29C illustrate an embodiment wherein the innerand outer members are rotated with respect to one another to achievecutting;

[0050]FIGS. 30A through 30D illustrate the way a tip, having a cuttingarrangement of one of the types described above, may be employed inconjunction with a suitable window to prevent the presentation of unduepressure, by the distal end of the filament, on tissue of the subject onwhom the invention may be used; and

[0051]FIGS. 31A and 31B, and 32A and 32B, illustrate a possibleconfiguration for a case for an embodiment similar to that of FIGS. 26Aand 26B.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0052] In order to provide an overall understanding of the presentinvention, the method, system, and device of the invention will bediscussed with reference to the application of the invention to providetissue bulking. However, it will be understood by persons of ordinaryskill in the art that the general method, system, and device, describedherein, are equally applicable to all cases in which filament injectionwould have value. A list of possible uses for the technology includes,but is not limited to, the injection of a filament-based system of drugdelivery into tissue, the subcutaneous or interstitial injection of afilament for the purpose of bulking, shaping, applying pressure, oradding other mechanical properties (such as springiness or rigidity),and the injection of a filament to act as a matrix or lattice in which acellular process may proceed (i.e. bone replacement, healing, implantedcellular scaffolding).

[0053] Other clinical uses include the injection into the body of afilament bearing other properties such as radiopacity, magnetism,radioactivity—radiation, or fluorescence, all suited for application asa clinical tracer or therapeutic agent. Similarly, the filament may havechemical properties which allow it to serve as a tracer of specifiedbiochemical processes or as a catalyst to stimulate or enhance desiredreactions within the tissue. This invention represents a new concept inthe delivery and retrieval of mass as well as of therapeutic anddiagnostic agents.

[0054] The applications of tissue bulking alone are manifold, once it isappreciated that tissue bulking may be achieved conveniently and at lowrisk using the method, system, and device of the present invention.Tissue bulking applications include, but are not limited to periurethralbulking of the urinary sphincter, support of the urethra, therapy ofvesicourethral reflux, prevention of esophageal reflux via thegastroesophageal sphincter, and treatment of the anal sphincter fortreatment of fecal incontinence. Other applications of tissue bulkingwhich may be achieved using the present invention include the bulking ofblood vessels, both internally or externally, in association with thetreatment of bleeding ulcers. The applications listed are given by wayof example, though it is to be understood that the scope of theinvention is not limited to the applications listed but includes allapplications wherein filamentous material is usefully injected into thebody.

[0055] As used in this specification and in the claims hereto appended,a material, provided in a threadlike form, will be referred to as“flaccid” if its buckling stress, measured in units of force per unitcross-sectional area of the material, is less than or comparable to theshear strength that is typical of soft body tissue (such as the dermis).Shear strength is expressed in the same units as stress. Bucklingstress, as is known in the mechanical arts, refers to the force per unitarea applied axially to a member which causes deformation of the memberin a direction orthogonal to the axis of the member. It is also known inthe mechanical arts that the buckling stress of a member is proportionalto the off-diagonal compressive modulus, (i.e., the ratio of axialcompressive stress to the strain induced transverse to the axialdirection) and inversely proportional to the square of the ratio ofunsupported length to diameter of the member. Thus, the longer or finera thread is, the less force per unit area is required to cause it tobuckle.

[0056] Clearly, it is known that rigid, needle-shaped implements, suchas all manner of needles or staples, may be driven into tissue uponapplication of sufficient axial force along the direction of insertion.By way of contrast, the present invention teaches a method of insertingmaterials which are flaccid rather than rigid. In view of the definitionof “flaccid” provided above, flaccid materials are inherently incapableof being driven into tissue by the application of axial force. Thesematerials are referred to, collectively, as “filament.” Moreparticularly, as used in this specification and in the claims heretoappended, the term “filament” refers to a flaccid material, and mayinclude biocompatible materials such as polypropylene, Nylon,DACRON.TM., polybutylester, polybutylethylene, polyglycolic acid (PGA),and variations thereof, and any other material, naturally occurring,biological, or man-made, which has been chosen for a particularapplication on the basis of biocompatibility, biodegradability, or anyother desirable property. Other filament materials useful in particularclinical applications are composite, woven, or solid, and include silk,metal, ‘gut’, collagen, clastin, cartilage and bone. The term “filament”encompasses, particularly, all materials, such as polypropylene,currently supplied and used as suture material and referred to thereas.Additionally, the term “filament” encompasses the use of materialshaving shape memory, such as nitinol, which may be used to particularclinical advantage. Whereas many of the foregoing materials may beformed into a wire-shaped member that is not flaccid as defined herein,the term “filament” in this description and the accompanying claims islimited to the embodiment of such materials in their flaccid forms.

[0057] Since the “filament” is flaccid, it will be appreciated thatmaterials of this category, if pressed, unguided, against the surface ofbody tissue, are likely to buckle rather than to cleave the surface,penetrate into the body tissue, or expand or dissect a space into thetissue.

[0058] When a filament is bent, such as under its own weight or due tocompressive buckling, the inner regions yield under compression. Forceapplied to the distal end of a bent filament by driving it against asurface is no longer truly axial and has a vector component which leadsto further bending. Plastic deformation may inhibit the return of thefilament to the original configuration even after removal of the load.However, the filament need not undergo any plastic deformation if it issuitably introduced and trapped within the body tissue, in accordancewith the present invention.

[0059] In the prior art, suture is treated as a flaccid material in thatit is pulled through tissue, as by a needle or tweezers, rather thanpushed. For suture or other filament sufficiently fine, large forces perunit cross-sectional area can be developed, using the teachings of thepresent patent, over small cross sectional areas. The force per unitarea applied by the tip of the filament can readily exceed the shearstrength of the body tissue so that the filament can thereby cleave andpenetrate the tissue. The recognition of this ability of a filament,using the methods of this invention, to penetrate body tissue, enablesthe host of clinical applications which are described herein.

[0060] As used in this description and in the appended claims, a“portal” for insertion of filament into the body refers to any naturallyexisting or created opening into the body or a tissue. The inventionteaches the insertion of filament into the vicinity of a tissue, where,as used in this description and in the appended claims, a “vicinity”includes at least a portion of the tissue itself, as well as its walls,and proximate tissue or body cavity. Since some tissues may be toosmall, fragile, or sensitive to permit direct insertion of filament,filament may be inserted, in accordance with the teachings of thepresent invention, into proximate tissue that is near but not directlyassociated with the target tissue.

[0061] Additionally, insertion of filament may be achieved via a vas,where, as used in this description and in the appended claims, the term“vas” refers to any duct, vessel, passageway or cavity occurring in thebody, either by natural anatomical formation or through surgicalintervention.

[0062]FIG. 1 illustrates a filament injection device 1 in accordancewith a preferred embodiment of the present invention. Here a needle 6 isinserted through the skin 2 into the body 3. A small filament 5 isinjected into an interstitial space 4. The needle 6 is attached to ahousing 7 which has an inlet 11 for fluid, a fluid control 8 for fluidinjection, an injection control 9 to advance the filament, and a cutcontrol 10. Those skilled in the art will recognize that needle 6 mayalso be a rigid, flexible, deformable, malleable, semi-rigid orsemi-flexible cannula or catheter inserted percutaneously,endoscopically or transvascularly. Further, filament 5 may also be aresorbable or non-resorbable suture, wire, or any of the other materialscomprised within the definition of “filament” given above. This filamentmay be a composite material embedded with drugs, cells, or radioactivesubstances. The combination of drugs with polymer to provide programmedrelease of the drugs within the body is known, as described in A. Loh,Controlled Release of Drugs from Surgical Suture, 1987, which is hereinincorporated by reference. The insertion into the body of a filamentwhich has been preloaded with a therapeutic or diagnostic agent, whetherby techniques of embedding or impregnating within the filament materialor otherwise bonding to the filament, whether at the time of manufactureor at the time of insertion into the body, is included within the scopeof the invention. While no other working channels are shown in thedevice, those skilled in the art will recognize that the modification ofthe device to permit additional instrumentation to be passed within oralong-side the device does not depart from the invention. Such otherchannels may be provided for introducing energy guides, wires,endoscopic visualization devices or surgical tools. The device as shownwould be easily advanced into the periurethral space for tissue bulkingor drug delivery to treat incontinence, or the perivascular space forvenous reconstitution or drug delivery, or the interstitial space withina tumor for chemotherapy, radiation or magnetic thermal therapy.

[0063] In this specification and in the appended claims, the term“distal” denotes the end of the filament injection device 1, or the endof any of the component parts of filament injection device 1 such asconduit 6, which is located toward the point of delivery of filament 5into the body 3. Conduit 6 serves as the delivery cannula through whichfilament 5 is introduced into the body of the subject. Similarly, inthis specification and in the appended claims, the term “proximal”denotes the end of the filament injection device 1 or the end of any ofthe component parts of filament injection device 1 which is located awayfrom the point of delivery of filament 5 into the body 3. Because of theneed to minimize the diameter of distal end 12 of filament injectiondevice 1, in order to avoid leaving a large hole in the body 3 of thesubject, the bulkier suture feeding mechanism typically resides in thebulkier proximal section 7 of the device. Therefore, the feedingmechanism, described below, cannot pull on the filament but must push itforward. In order to allow for pushing a flaccid material into the body,the zone between feeding mechanism 7 and conduit 6 over which filament 5is unsupported must be kept to a minimum. In some preferred embodimentsof the invention, there is no unsupported length of filament 5, while,in other embodiments, a length of filament 5 is unsupported, and is,typically, no larger than three times the characteristic diameter of thefilament.

[0064] Referring now to FIG. 2, wherein the principal components of afilament feeding device used, in accordance with a preferred embodimentof the invention, to advance the filament into the tissue. Inner cannula14 is a tubular section having a diameter closely matched to thediameter of filament 5 for which inner cannula 14 provides support.Inner cannula 14 prevents filament 5 from buckling or jamming as aresult of the axial force pushing it into the body, and is, in turn,retained axially within a coaxial outer cannula 15. In alternateembodiments, inner cannula 14 may be retained by other manner ofmounting arrangements, to include channels, as is well known to a personof ordinary skill in the art.

[0065]FIG. 3A shows a cutout window 16 in the proximal section of innercannula 14. Cutout window 16 exposes a small section of filament 5 andallows actuating pad 17 to couple filament 5 and inner cannula 14 to anactuator mechanism 502 (shown in FIG. 5). Actuating pad 17 is referredto, functionally, as a “gripper.” FIG. 3B shows actuating pad 17depressed in a direction 18 transverse to filament 5 in order to engageit securely. FIG. 3C shows the advancement, by means of the action ofactuator mechanism 502 (shown in FIG. 5), of actuating pad 17 to theleft, and the advancement, along with actuating pad 17, of both innercannula 14 and filament 5 such that a length of filament 5 equal to thedistance 19 of motion of actuating pad 17 is urged into the body tissue.

[0066]FIGS. 4A and 4B illustrate the next step of the filament feedingaction, the reset part of the cycle, wherein actuating pad 17 isretracted from contact with filament 5 and is urged proximally, inretrograde direction 404, such that inner cannula 14 and actuating pad17 return to their original proximal position. In a preferred embodimentof the invention, inner cannula 14 has a distal segment 408 and aproximal segment 410, separated by containment spring 412. The direction406 of retraction of the distal segment 408 of inner cannula 14 isreferred to as the retrograde direction. During the reset part of thefilament feeding cycle, the filament 5 itself is prevented from comingback out of the body tissue by means of friction brake 402, locatedproximally to actuating pad 17, which secures filament 5 within theproximal segment 410 of inner cannula 14. Retraction of distal segment408 of inner cannula 14 is achieved, in a preferred embodiment of theinvention, by means of the force supplied by containment spring 412 incompression. The feeding action described allows a high force per unitcross-sectional area to be applied in advancing filament 5 into the bodytissue while a lower force is supplied by containment spring 412 toretract the distal segment 408 of inner cannula 14.

[0067] Referring now to FIG. 5 wherein the components of a filamentfeeding mechanism, designated generally by numeral 500, are shown inexploded view. Actuator mechanism 502 is shown to comprise a thumb pad504 which the physician uses to advance slider 506 forward to a stop inthe slider guide 508. By pressing on distal part 505 of thumb pad 504,the physician causes activator pad 17 (shown in FIGS. 4A and 4B) to comeinto contact with filament 5 (shown in FIG. 4A), and, as he also urgesthumb pad 504 forward, he feeds a discrete amount of filament 5, paidoff of spool 510 along feed axis 512, into the body tissue, according tothe mechanical principle described above with reference to FIG. 3. In analternate embodiment, the actuation of filament advancement isaccomplished by means of an electrical stepper, using mechanicalprinciples known to persons having ordinary skill in the art. The amountof filament fed in each advancement step of the feeding cycle is,typically, on the order of 5 mm. However, design and adjustment offilament feeding mechanism 500 can provide for a longer or shorterlength of filament to be fed in each advancement step, indeed, anydesired length of filament may be provided per advancement step. Toreset the mechanism for the next feeding, the physician depresses theproximal part 503 of thumb pad 504, thereby freeing pawl 514 from aratchet rack 522 contained in a body 524, and allowing thumb pad 505 anddistal segment 408 of internal cannula 14 (shown in FIG. 4B) to retract,according to the principle discussed above with reference to FIGS.4A-4B. Since the actuating pad 17 is now held up away from the filament5 and since the suture is held in its forward position by brake 402, thelength of filament previously fed remains in the body tissue.

[0068]FIG. 6 shows a cross sectional view of the distal tip of afilament feed mechanism, according to a preferred embodiment of theinvention. It has been found that if the tip 600 of the filament 5itself is allowed to push straight into the body tissue at the start ofthe procedure, it can occasionally penetrate the tissue and travelfurther ahead than clinically indicated, and, instead of remaining inthe area surrounding tip 602 of outer cannula 15 and creating theintended localization of filament for purposes of tissue bulking, vasocclusion, or any of the other clinical purposes of filamentlocalization. A solution to this problem, according to a preferredembodiment of the invention, is to provide cutout window 604 in outercannula 15, immediately proximally to tip 602. As the filament is urgedforward, according to the feeding method described above, or otherwise,it bends and then buckles toward the only opening in the area: window604. Thus the filament enters the body tissue in a gentle sidewaysmanner, presenting to the tissue an area large enough that the force perunit area is insufficient to shear the tissue and to cause inadvertentpenetration. Once a filament coiling process is started in this manner,the implanted filament remains within the target region of the body. Inorder to point the outer cannula window 604 in the direction in whichthe filament is to be applied to the tissue, the outer cannula 15 isfully rotable about its axis in fixed increments, typically 45-degreeincrements. A ball plunger arrangement holds the outer cannula in thechosen orientation, according to mechanical principles known to a personof ordinary skill in the art.

[0069] When sufficient filament has been introduced into the body toachieve the requisite tissue bulking or other clinical objective, thephysician cuts the filament before withdrawing the device. Thus, inaccordance with the present invention, the filament stored in thefilament injection device is longer than the amount of filament which isintended to be used in the application at hand. Thus, the desired lengthmay be determined during the course of the procedure and severed afterit is deployed into the body of the subject. One method of cutting thefilament is described with reference to FIGS. 7A and 7B. In a preferredembodiment of the invention, stop 702 is provided within lumen 704 ofouter cannula 16. Distal end 706 of distal segment 412 of inner cannula14 is provided with a sharpened edge. Thus, when sufficient filament 5has been injected to constitute the clinically indicated implant 700,distal segment 412 of inner cannula 14 is thrust against stop 702,cutting off filament 5. To allow the inner cannula 14 to advance as faras the cutting stop 702, a trigger 518 (shown in FIG. 5) must beactivated by the physician, releasing slider stop 520 (shown in FIG. 5)which, otherwise, prevents the advance of inner cannula 14 to the pointof cutting off the filament. In an alternate but equivalent embodiment,the sharpened edge is provided within lumen 704 of outer cannula 16,while, mutatis mutandis, the cutting stop is now provided at the distaledge of inner cannula 14. The cutting action for cutting off thefilament remains as described. In an alternate embodiment, the cuttingfunction is achieved by providing a high-tolerance fit of the innercannula 14 so that when the distal edge 706 of the inner cannula 14 ispushed past distal edge 606 (shown in FIG. 6) of window 604 (shown inFIG. 6), filament 5 is sheared. Shearing of filament 5 may also beachieved, alternatively, through rotation of inner cannula 14 withrespect to outer cannula, where shearing surfaces are provided on one orboth members, as would be apparent to a person skilled in the art.

[0070] Another method of cutting the filament is described withreference to FIGS. 7C and 7D. In an alternate embodiment of theinvention shown in FIG. 7C, conduit 708, which can be used inconjunction with any of the filament feeding mechanisms describedherein, is provided, at its distal end, with a torquable head 710containing window 712 within distal surface 714. Referring now to thecross sectional view shown in FIG. 7D, torque is transmitted to rotatetorquable head 710 via torque wire 716 which runs through conduit 708 sothat torque may be applied at its proximal end (not shown). Whentorquable head 710 is rotated, filament 5 is cut by blade inset 718,such that, upon withdrawal of conduit 708 from the body, the requisitelength of filament 5 is left in the body. In one embodiment of theinvention, a cannula 720 is provided through conduit 708, parallel tofilament 5, so that fluid or a guide wire may be introduce via cannula720 through port 714 in torquable head 710 into the body region intowhich filament 5 is being inserted.

[0071]FIG. 8 shows the detail of how the filament may be advanced intothe tissue. Within the lumen 26 at the tip of needle 6, the filament isheld in a position against the wall by struts 24 and 25. Shaft 27 has ahead 21 and a channel 22 spaced back from the tip of head 21 a smalldistance. As shaft 27 is advanced, head 21 comes in contract withpartial pivot 23 and is forced downward, engaging filament 5. As shaft27 continues to advance, filament 5 is pushed forward as head 21subluxes under pivot 23. With the continued advancement of shaft 27,eventually channel 22 aligns with pivot 23, permitting it to spring backinto its original shape, disengaging filament 5. Then, as shaft 27 iswithdrawn, head 21 rides over pivot 23, losing contact with filament 5preventing inadvertent withdrawal of filament 5. Finally the cycle iscomplete when head 21 pops over pivot 23 and snaps back into itsoriginal shape and position at the start of the cycle.

[0072]FIG. 9 illustrates a schematic of a powered drive system forcycling the shaft 27 with the touch of a button. When switch 38 isturned on, power to a small motor 35 turns a set of gears 33 and 34which drive a bar linkage 32 riding in a channel 31. The bar linkage 32is attached to the shaft 27 at the point within or near the channel 31.Power source 37 may be connected to processor 36 which may be capable ofcorrelating, tracking or controlling ‘on-time’ as it relates to the massof filament deposited within the body. Alternatively, those skilled inthe art will recognize that various mechanical methods are easilyapplied which would allow the shaft to be man-powered or mechanicallydriven.

[0073]FIG. 10 illustrates a layout of an embodiment of the system. Fluidcontrol 8 may drive fluid stored in vessel 43 forward through the tip ofneedle 6. A principal purpose of the fluid is to dilate the space to beoccupied by the filament; in this connection, the fluid may be asuitable liquid such as saline, although the fluid may also oralternatively include anesthetic, antibiotic, or other medication. Othermethods may also be used for dilation of the space, including inflationof a temporary balloon. Alternatively, the implantation of the filamentitself may be used to cause dilation of the space. Further, it isenvisioned that an endoscope may desirably be inserted into the spacebefore, during or after the treatment to ensure proper placement.Injection port 11 provides access to vessel 43. Injection control 9 isattached to drive mechanism 45 which is subsequently linked to shaft 27.As discussed earlier, the movement of shaft 27 drives filament 5forward. Spool 41 stores filament 5 prior to delivery and acts as afilament reservoir as filament 5 is advanced. If only a portion offilament 5 is required, filament 5 may be severed by cutting mechanism42 activated by cut control 10.

[0074]FIG. 11A is a cross section of the result after the device hasbeen used to coapt the walls of a tubular structure 52, or vas (asdefined above), within the body. The tubular structure 52 may be anywithin the body such as a ureter, urethra, vein, artery, bowel,esophagus, stomach, oropharynx or sphincter. Other body tissue 54surrounds wall 53 of tubular structure 52. Filament balls 51 have beenplaced on either side of the tubular structure to create an increase inresistance to flow, provide a site for local drug delivery or supportinternal structures such as valves. Placement of filament balls 51within exterior body tissue 54 is shown by way of example, whileplacement within or proximal to wall 53 is also within the scope of theinvention.

[0075]FIG. 11B illustrates another embodiment of the invention, in whichfilament injection device 1 is applied in the treatment of an ulcer suchas a peptic ulcer of the duodenum, stomach, or lower esophagus. Conduit6 is shown supplying filament (not shown) into crater 56 of ulceratedmucosa 57 surrounding blood vessel 58. By inserting the fiber into thevicinity of blood vessel 58, it is possible to stop the supply of bloodto the ulcer.

[0076]FIG. 12 illustrates an embodiment of the invention for removing afilament in the body after it has been placed. Cannula 61 is advancedinto the center of the filament ball and then hook 62 is pushed forward.Once a strand of the filament has been captured or snagged by the hook62, the filament and the device may be withdrawn.

[0077] The present invention may be used for purposes other than bulkingof tissue. In particular, the device of the present invention may alsobe used for the delivery of suture for purposes such as sewing,ligation, and anastomosis. In this mode, the device may be passed intoand through tissue, advancing a singular loop of suture before beingpulled back. As seen in FIGS. 13A-13C, the procedure may permit thesuture to be passed through and around tissue without the requirement ofmanipulating a loose needle. Here needle 71 is passed through tissue 72with the aid of grasper 73. Once through the tissue, filament 74 isadvanced and grasped by grasper 73; then the needle 71 may be withdrawn.After the filament has been deployed as desired, the filament may besevered, and once the filament is severed, a knot may be tied. Anotheruse is shown in FIG. 7C. Here, several insertions of needle 71 can beperformed to create a series of linked loops 75 which can ultimately betensioned and tied.

[0078]FIG. 14 illustrates the mechanism through which particles may beinjected into the body, in accordance with another embodiment of theinvention, in order to accomplish the same purposes as taught in thisspecification with respect to the injection of filament. Again, as inthe case of filament, the particle may be one of any of the currentlyavailable biocompatible materials, including but not limited to silk,plastic, polymer, metal, cells, collagen, bone or other materialdescribed above in connection with the definition of the term“filament”. Specifically, as with the filament, the material may also beone of any available suture materials such as polyglycolic acid (PGA),polytetrafluoroethylene (PTFE), DACRON.TM., polypropylene, nylonpolyester, silk, polybutylester, stainless steel, titanium, chromic gut,polybutylester, cotton, or silver. Here, particles 80 are shown beinginjected into a created cavity 86 within the body 87. Particles 80 arepassed down the shaft 81 along with a pressurized fluid 83 from storagechamber 88 propelled by pressure source 84. The fluid is then withdrawnvia channel 82 by suction source 85. The pressure and suction sourcesmay be manually activated or may be electronically controlled orotherwise controlled. The pressurized fluid may be also a gas likeCO.sub.2, but may also be saline, dextrose, antibiotic or otherbiocompatible agent that acts either passively to assist the particlesto reach their destination, or performs another purpose such asproviding antibiotic protection, activating the particles once in place,or providing a means through which the particles may be held in oneplace. The particles may be of any size which permits them to beintroduced down the shaft of a cannula, catheter or needle.

[0079]FIGS. 15A and 15B show respectively a descended bladder of afemale subject and the same bladder after it has been elevated by use ofa filament implanted in accordance with an embodiment of the invention.In these figures the bladder 91 and bladder neck 93 are shown inrelation to the pubic bone 92, the vagina 94, uterus 95, and anus 96. Inaccordance with this embodiment, as shown in FIG. 15B, filament 99 isimplanted in tissue so as to provide elevation of the bladder in theregion of the bladder neck 93. The filament 99 is inserted using cannula98 to which is affixed delivery tool 97. Detailed descriptions of thedelivery tool 97 are provided below. It will be appreciated that otherorgans and tissue may be similarly supported or relocated using similartechniques.

[0080]FIG. 16 shows an embolism that has been achieved in a blood vesselby means of a filament implanted in accordance with an embodiment of theinvention. Here filament 106 has been inserted to create an embolism inthe blood vessel 101. Insertion of the filament is achieved first byappropriate placement of guide wire 103 in a manner known in the art.Catheter 102 is equipped with a cutter 104 and a side hole 105 fromwhich emanates the filament 106. After an appropriate length of filamenthas been implanted in the blood vessel 101, the cutter 104 is used tocut the filament at the point where it emanates from the catheter, andthe catheter and guide wire are thereupon removed. A technique similarto this may be utilized in other tissue to prevent flow or leakage.

[0081]FIG. 17 shows an aneurysm that has been filled by means of afilament implanted in accordance with an embodiment of the invention. Inthis figure filament 106 is used to fill aneurysm 111 in blood vessel101. Again insertion is achieved utilizing guide wire 103 over whichcatheter 102 is inserted. The catheter 102 is used to carry the filament106, which emerges from side hole 105 and is cut, after a desired lengthhas been implanted, by cutter 104.

[0082]FIGS. 18A through 26 illustrate various embodiments of theinvention for achieving the movement of a filament along a desired pathso as to permit implantation of the filament. It will be appreciatedthat these embodiments, which provide an engine for the advance offilament in a catheter, may be incorporated in a variety of deliverytools. One type of delivery tool may be in the form of a completelyhand-held unit, which includes a spool or cartridge of filament, thefilament-advance engine, as well as a fitting to receive a catheter orother insertion device. The entire unit may be disposable or it may beprovided with features making it able to withstand sterilization in anautoclave or by other means. Similarly, it is within the scope of thepresent invention to put the filament-advance engine in a first case,along with a cassette or spool of filament, and permit the case to beplaced on a table or otherwise suspended or mounted in a convenientlocation for use. In this connection, there may be attached to the casea disposable cannula for carrying the filament to the site of theoperation. The cannula may be fitted with a suitable handle and controlarrangement, as well as a tip. The cannula, handle and tip may all beimplemented as disposables or alternatively as sterilizable items. Thefilament advance engine may be motor driven or hand driven. In the eventthat it is hand driven, power to the device may be provided bysuccessive squeezes of a trigger or lever against a handle for the tool;the extent of the squeeze may regulate the extent of the advance of thefilament.

[0083] As discussed above, the filament may be a monofilament made, forexample, of a suitable polymer such as nylon, polybutylester, orpolypropylene. Alternatively the filament may be braided. In the case ofa braided filament and in some instances in the case of a monofilament,the flexibility of the filament may make it difficult to advance, evenin a cannula. Accordingly, in an embodiment of the invention, thefilament is treated with a suitable stiffening agent, typically at atime prior to placement of the filament in the delivery tool. Thisstiffening agent is preferably made up of an absorbable material, suchas starch, but it is within the scope of the invention to utilize othermaterials that provide requisite stiffness and avoid the irritation oftissue. The stiffness of a filament may also be varied throughtemperature-effects in situ, such as by use of the temperature-dependentproperties of polymers and other materials, as known to persons skilledin the art.

[0084] The filament may be provided to the delivery tool in a spool orother convenient form. In this respect, it should be noted that it istypical for many filament materials to have some shape memory, and themanner in which the filament is spooled can affect the manner in whichthe filament responds as it emanates from the delivery tool and even asit is being advanced through the delivery tool. Accordingly the spoolingof the filament may be implemented in a manner designed to providecharacteristics suitable for the particular implantation task at hand.Where it is desired, for example, to have the filament tightly occupy asmall volume, the filament may be wound on a spool of small diameter andheated in place on the spool to cause memorization of the small-radiusassociated with the spool. Note that the small-radius may be retained inshape memory even if the filament must be subsequently be rewound onto adifferent spool for insertion into the delivery tool. It is alsopossible, of course, to sterilize the filament after it has been woundonto the spool.

[0085]FIGS. 18A and 18B illustrate an embodiment for achieving movementof a filament utilizing a pair of conveyor belts symmetrically engagedagainst the filament. Here the conveyor belts 121 and 122 engage againstthe filament 123. The belts are driven by one or more of the pulleys 124about which they are mounted. The filament 123 is fed through an inputconduit 126 into an output conduit 125 that is located preferably closeto the location where the filament emerges from the pair of belts so asto prevent bunching. The outer diameter of output conduit 125 may beground down to allow close proximity between output conduit 125 andconveyor belts 121 and 122.

[0086]FIG. 19 illustrates an embodiment for achieving movement of afilament utilizing a toothed drive wheel against which the filament isengaged by an idler wheel. The toothed drive wheel is shown as item 131and the idler wheel as item 132. Also shown are the input conduit 126and the output conduit 125. The outer diameter of output conduit 125 maybe ground down to allow close proximity between output conduit 125 anddrive wheels 131 and 132.

[0087]FIG. 20 illustrates an embodiment, similar to that of FIG. 19,utilizing a toothed drive wheel against which the filament is engaged byan idler wheel, but wherein the filament is also engaged against thedrive wheel by a guide having an arcuate surface that general conformsto the radius of the drive wheel. Here the guide is shown as item 141,and it replaces input conduit 126. The advantage of this arrangement isthat it increases the length of the filament 123 that is engaged bydrive wheel 131 and therefore ensures better traction by the drive wheel131.

[0088]FIGS. 21A and 21B illustrate an embodiment, similar to that ofFIG. 19, utilizing a toothed drive wheel 131 against which the filamentis engaged by an idler wheel 132, but wherein the idler wheel at 132 issoft.

[0089]FIG. 22 illustrates an embodiment for achieving movement of afilament utilizing a toothed drive wheel against which the filament isengaged by a tubular guide. In this figure the drive wheel 131 operatesthrough a slot formed in the tubular guide 161. This embodiment has theadvantage of achieving a complete merger of the input and outputconduits.

[0090]FIGS. 23A and 23B illustrate an embodiment for achieving movementof a filament utilizing a drive wheel against which the filament isengaged by an idler belt. In this figure the drive wheel 171 is shown toengage the filament 123 against belt 173 that is disposed around pulleys172. The filament emerges through exit conduit 125.

[0091]FIGS. 24A through 24E illustrate an embodiment for achievingmovement of a filament utilizing a pair of axially reciprocating tubularmembers, within which the filament is disposed, in conjunction with aperiodically clamping finger. In these figures the tubular members 181and 182 operate within sleeve 185. Tubular member 181 is caused to movewithin the sleeve 185 carrying the filament 123 with it during thefeeding phase. The finger 186 is spring loaded to cause the tip 187 ofthe finger to press against the filament 123 in channel 189 of thetubular member 181. During the reset phase, filament 123 is trapped fromretrograde movement by finger 186. In FIG. 24A, the tubular member 181is fully advanced, having just completed a stroke. In FIG. 24B, the tip187 of finger 186 has been caused to move away from the filament 123 inchannel 189 owing to action of the sliding cam 188. The disengagement ofthe finger 186 from the filament permits the tubular member 181 to slideaxially to the left in sleeve 185 without causing any motion of thefilament in a leftward direction. The assembly consisting of the tubularmember 181 and the finger 186 with its cam 188 is thus shown fullyretracted in FIG. 24C. In FIG. 24D the cam 188 has been slid to theright, permitting the finger 186 to engage the filament 123 at the tip187 of the finger. The finger so engaged is shown in FIG. 24D. At thispoint the tubular member and finger assembly can then advance to theright as shown in FIG. 24A. In order to maintain the shape of thefilament 123, between the termination of the tubular members 181 and 182is a spring 183 within the sleeve 185. These springs surround thefilament and tend to reduce any bowing of the filament that wouldprevent transmission of force along its length. FIG. 24E shows theassembly of FIGS. 24A through 24D rotated 90.degree. Here it can be seenthat the sliding cam 188 may receive reciprocating power at tab 188 a. Aslot 188 b is formed in a portion of the cam through which protrudeposts 181 a and 181 b that are coupled rigidly to the tubular member181. Accordingly, when the cam is urged to the right and when post 181 ahits the leftmost limit of slot 188 b, the power provided at tab 188 awill cause the tubular member 181 to move to the right. When the post181 b encounters the rightmost portion of slot 188 b, the tubular member181 will be moved to the left. This arrangement permits the samereciprocating power at tab 188 a to actuate both the cam 188 and thetubular member 181. As shown in certain other embodiments, it may benecessary or desirable to provide a suitable arrangement for applying aslight resistance to leftward motion of the filament when the tubularmember 123 is undergoing retraction from the fully advanced position.

[0092]FIGS. 25A through 25E illustrate an embodiment similar to that ofFIGS. 24A through 24E but in which the coil springs of the latterfigures are supplanted by complementary mating extensions of the tubularmembers. In this case the tubular member 181 includes the extension 191and the tubular member 182 includes the extension 192. The strokes foradvancing the filament in the case of FIGS. 25A through 25D correspondto the strokes described previously in connection with FIGS. 24A through24D. Similarly FIG. 25E corresponds to FIG. 24E. It can be seen in FIG.25C that as the tubular members 181 and 182 are separated, some guidancefor the filament 123 is provided by the extensions 191 and 192 of thetubular members 181 and 182 respectively. Although only a single pair191 and 192 of extensions are shown, it is within the scope of thepresent invention to provide a plurality of extensions to each of thetubular members 181 and 182 in such a way that the extensions meet witheach other when the tubular members 181 and 182 are fully advanced toprovide the effect of a single conduit; and when the tubular members areseparated, a plurality of extensions are present around the end of thetubular member to provide support for the filament.

[0093]FIGS. 26A and 26B illustrate an embodiment for achieving movementof a filament utilizing a pair of arms that are caused to reciprocateaxially while being alternately opened and closed at the opposite endsof each stroke. In this figure are shown arms 201 and 202 that includetips 203 and 204 respectively for pinching filament 123. Cam assembly205 is arranged to cause successive opening and closing of the arms 201and 202 and therefore of the tips 204 and 203. The cam assembly 205 isalso configured to cause reciprocating motion of the arm assembly in theleft-right direction, that is, in the direction of the length offilament 123. Furthermore, the cam assembly 205 is configured so that acycle of operation causes the tips 203 and 204 to grab the filament 123when the arm assembly is in its leftmost position and to retain grip onthe filament until the arm assembly has reached its rightmost position.At this position, on the arm assembly is caused to open, whereupon gripof the tips 204 and 203 on the filament 123 is released. In FIGS. 26Aand 26B can be seen spool 207 of material constituting filament 123 aswell as output conduit through which the filament 123 runs after exitingfrom the tips 204 and 203. In the output conduit 207 is a channel intowhich protrudes pawl 206. The pawl is angled in such a way that itoffers little resistance to forward motion of the filament, but offersconsiderable resistance to rearward motion of the filament (forwardmotion being to the right). If it is desired to retract the filament 123the arms 201 and 202 may be opened and the spool 207 may be powered toeffectuate rewinding, in which case the pawl 206 may also be optionallydisengaged from the filament. Alternatively, the spool 207 may be drivenin reverse through a clutch arrangement and the advance mechanismconstituting the two arms may be run backwards.

[0094] In the case of the filament-advance engines described above, itis possible to monitor a number of parameters including the number ofrevolutions of the filament spool, or (directly) the length of filamentbeing unspooled, as well as the number of reciprocations or drivemovements associated with attempts at moving the filament. The drivemovements can be matched against actual filament movement in order todetermine whether slippage is taking place. If it is determined thatslippage is present, an alarm state may be entered to permit appropriatecorrective action.

[0095]FIGS. 27A through 30D illustrate embodiments of the invention inwhich a region proximate to a tip of a cannula carrying a filament isprovided with an arrangement, for cutting the filament, utilizing aconcentrically disposed member and a window in both members throughwhich the filament is placed and severed.

[0096]FIGS. 27A and 27B illustrate an embodiment wherein the outermember is pulled proximally with respect to the inner member to achievecutting. In FIG. 27A there is shown inner member 212 in relation toouter member 213. Filament 211 is carried in the lumen of the innermember 212 and emanates from window 214. In FIG. 27B the outer member213 is pulled proximally with respect to the inner member 212 so that ascissors action results from the passage of edge 214 on the outer member213 by the edge 215 of the inner member 212. The result is the cuttingof filament 211 at the intersection of edges 214 and 215. The relativemotion of the inner member and outer member 213 causes the window 216 inthe outer member to cease to coincide with the window 214 of the innermember. It should be noted that design of the edges 214 and 215 may beimplemented in a variety of fashions. In FIGS. 27A and 27B, 214 isbeveled and 215 is straight. Alternatively 215 may be beveled and 214may be straight. In fact a successful scissors action may be achievedwhen windows 214 and 215 are both straight, particularly if the windows214 and 216 are configured in such a way that the intersection of theedges 214 and 215 moves somewhat helically as outer member 213 is movedproximally.

[0097]FIGS. 28A and 28B illustrate an embodiment wherein the outermember is pushed distally with respect to the inner member to achievecutting. In this figure the design is similar to that shown in FIGS. 27Aand 27B. Here pushing the outer member 221 distally causes passage ofthe beveled edge 222 of outer member 221 by the straight edge 223 ofinner member 212 and consequent cutting of filament 211. Equivalently,edge 223 may be beveled and 222 may be straight, or both may be beveled,or neither may be beveled.

[0098]FIGS. 29A through 29C illustrate an embodiment wherein the innerand outer members are rotated with respect to one another to achievecutting. The outer member 231 is permitted to rotate around inner member212 to cause cutting of the fiber 211 emerging through the window 232.The effect of the rotation can be seen in the cross section taken at BBand shown in FIGS. 29B and 29C. The effect of the rotation is to causeedge 233 of outer member 231 to slice the filament 211 against the edge234 of inner member 212.

[0099]FIGS. 30A through 30D illustrate the way a tip, having a cuttingarrangement of one of the types described above, may be employed inconjunction with a suitable window to prevent the presentation of unduepressure, by the distal end of the filament, on tissue of the subject onwhom the invention may be used. In FIGS. 30A through 30D is shown a pushcutter arrangement similar to that shown and discussed in connectionwith FIGS. 28A and 28B. There is thus an outer member 221 having a bevel222 and an inner member 212. A window 243 is provided in the innermember to permit the emergence of a loop of filament 211. The end of thefilament may be suitably captured in region 242 near the tip 241 ofinner member 212. Using a filament-advance engine in accordance with asuitable embodiment such as described above, the filament may be causedto leave the exit window 243 while keeping the end of the filamentengaged near the tip 241. The advantage of following such a procedure isthat the loop of filament material will exert less pressure on tissuethan would a free end; in this way the risk of lesion to surroundingtissue is reduced. In the course of advancing the filament into tissue,the end of the filament will eventually leave the tip region 242;however at this point, owing to the presence of a substantial portion offilament length already present, the forces associated with movement atthe end of the filament are dramatically reduced. After a desiredquantity of filament has been implanted, the outer member 221 is used tocause cutting of the filament 211. Cutting is initiated therefore bymoving outer member 221 distally, as shown in FIG. 30C. In FIG. 30D, thefilament 211 has been cut, and it can be seen that by further advancingthe filament. The end will again be engaged in tip region 242, so thatwhen desired the window 243 can again be opened by withdrawal of theouter member 221 and the process begun anew.

[0100] It will be appreciated that the size of the exit window 243 maybe selected to take into account the particular nature of theimplantation desired and the filament employed. For example, if it isdesired that the material be concentrated in a very small region or ifthe filament is very flexible, then a smaller exit window may beappropriate, whereas if a larger region is to be treated or a stifferfilament is used, a larger exit window will be indicated.

[0101] In general, when a guide wire is utilized in connection with acannula used for filament implantation herein, the guide wire may beutilized in a separate lumen of the cannula. Alternatively, it is withinthe scope of the present invention to utilize a common lumen for boththe guide wire and the filament.

[0102]FIGS. 31A and 31B, and 32A and 32B, illustrate a possibleconfiguration for a case for an embodiment similar to that of FIGS. 26Aand 26B. In this configuration a cannula for insertion of the filamentmay be attached at fitting 251, and a handle 253 for actuating a cutteris also provided. A cable assembly 254 is removably attachable to thebody of 255 to supply rotational power to the tool. Knob 252 is coupledto an internally located spool of filament.

[0103] The described embodiments of the inventions are intended to bemerely exemplary and numerous variations and modifications will beapparent to those skilled in the art. All such variations andmodifications are intended to be within the scope of the presentinvention as defined in the appended claims.

What is claimed is:
 1. A method for modifying a tissue property of asubject, the method comprising: a. providing a quantity of filament; b.opening a portal in the body of the subject; c. inserting the filamentthrough the portal into a region in the vicinity of the tissue; and d.localizing the filament in the region so as to modify the tissueproperty.
 2. A method according to claim 1, wherein the propertyincludes at least one of the mass, bulk, orientation, rigidity,flexibility, springiness, and permeability of the tissue.
 3. A methodfor bulking tissue of a subject, the method comprising: a. providing aquantity of filament; b. inserting the filament into a region in thevicinity of the tissue; and c. localizing the filament in the region soas to achieve bulking of the tissue.
 4. A bulking method according toclaim 3, wherein the step of inserting includes the step of introducingthe filament with the aid of an endoscope.
 5. A bulking method accordingto claim 3, wherein the step of inserting includes the step ofintroducing the filament with the aid of a laparoscope.
 6. A bulkingmethod according to claim 3, further comprising the step of drivingfluid through the portal into the tissue to dilate the region to beoccupied by the filament.
 7. A method for coapting walls of a vas toincrease the resistance to flow of a bodily material within the vas, themethod comprising: a. providing a quantity of filament; b. inserting thefilament into the vicinity of the wall of the vas.
 8. A method foroccluding a vas of a subject, the method comprising: a. providing aquantity of filament; b. inserting the filament into the vas; and c.localizing the filament in a region so as to achieve the occlusion ofthe vas.
 9. An occluding method according to claim 8, wherein the stepof providing filament further comprises the step of training thefilament to take a preset shape.
 10. An occluding method according toclaim 8, wherein the step of providing filament further comprises thestep of providing filament that has been coated with an clottingcompound.
 11. A method for preventing pregnancy in a subject, the methodcomprising: a. providing a quantity of filament; b. inserting thefilament into a region in the vicinity of the fallopian tube of thesubject; and c. localizing the filament in the region so as to achievethe occlusion of the fallopian tube.
 12. A method for sterilizing asubject, the method comprising: a. providing a quantity of filament; b.inserting the filament into a region in the vicinity of the ductusdeferens of the subject; and c. localizing the filament in the region soas to achieve the occlusion of the ductus deferens.
 13. A method forclotting of an ulcer fed by a blood vessel, the method comprising: a.providing a quantity of filament; b. inserting the filament into aregion in the vicinity of the blood vessel; and c. localizing thefilament in the region so as to stop the supply of blood to the ulcer.14. An ulcer clotting method according to claim 13, wherein the step ofproviding filament further comprises the step of preloading the filamentwith at least one therapeutic agent.
 15. An ulcer clotting methodaccording to claim 13, wherein the step of providing filament includesthe step of providing electrically conducting filament and the methodfurther comprises the step of applying radio-frequency energy forheating the filament.
 16. A method of inserting a filament into thebody, the method comprising: a. providing a filament having an end withshape memory; b. opening a portal in the body of the subject; c.inserting the filament through the portal; and d. causing the filamentend to assume the shape in its memory.
 17. A method for treating anaortic aneurism having an aneurysmal pocket, the method comprising: a.delivering a stent graft percutaneously; b. providing a quantity offilament; c. inserting the filament into the aneurism; and d. localizingthe filament in a region of the aneurysm so as to clot off theaneurysmal pocket.
 18. A method for treating a bleeding esophageal varixin a subject, the method comprising: a. providing a quantity offilament; b. inserting the filament into a region in the vicinity of thebleeding varix; and c. localizing the filament in the region so as toocclude the bleeding varix.
 19. A method for treating a bleedingesophageal varix according to claim 18, wherein the step of providingfilament further comprises the step of providing filament preloaded withat least one therapeutic agent.
 20. A method for treating a bleedingesophageal varix according to claim 18, wherein the step of providingfilament includes the step of providing electrically conducting filamentand the method further comprises the step of applying radio-frequencyenergy for heating the filament.
 21. A method for providing chemotherapyin a subject having malignant tissue, the method comprising: a.providing a quantity of filament preloaded with at least one therapeuticagent; b. inserting the filament into a region in the vicinity of themalignant tissue; and c. localizing the filament in the region.
 22. Amethod for releasing a drug into a subject, the method comprising: a.providing a quantity of filament; b. preloading the filament with atleast one therapeutic agent; and c. inserting the filament into the bodyof the subject.
 23. A method for catalyzing biochemical reactions in thebody of a subject, the method comprising: a. providing a quantity offilament having requisite catalytic properties; and b. inserting thefilament into the body of the subject.
 24. A method for monitoring ofbiochemical processes in situ, the method comprising: a. providing aquantity of filament; b. preloading the filament with at least onediagnostic agent; c. inserting the filament into the body of thesubject; and d. monitoring the response of the agent.
 25. A method forproviding birth control in a subject, the method comprising: a.providing a quantity of filament; b. preloading the filament with atleast one contraceptive agent; and c. inserting the filament into thebody of the subject.
 26. A method for supporting cell growth in asubject, the method comprising: a. providing a quantity of filament; b.inserting the filament into the subject; and c. localizing the filamentin a reticulate manner so as to form a matrix; and d. allowing theentrance of cells into the matrix.
 27. A method as in any one of thepreceding claims further comprising the step of injecting a fluid intothe body of the subject in conjunction with the filament.
 28. A methodfor sewing tissue, the method comprising: a. providing a quantity offilament; b. feeding an end of the filament into a hollow shaft having atip; c. inserting the hollow shaft into the tissue; d. advancing thefilament along the shaft into the tissue; and e. binding the filament soas to suture the tissue.
 29. A method for sewing tissue according toclaim 30, wherein the hollow shaft of steps (b), (c), and (d) has alongitudinal axis and the tip is deformed so as to lie off the axis tofacilitate curving the path of the filament into the tissue.
 30. Amethod for modifying a tissue property of a subject, the methodcomprising: a. providing a quantity of filament; b. feeding an end ofthe filament into a hollow shaft having a tip; c. inserting the hollowshaft into a region that includes at least a portion of the tissue; d.advancing the filament along the shaft into the tissue; and e.localizing the filament in the region so as to modify the tissueproperty.
 31. A method according to claim 32, wherein at least a portionof the shaft includes a passageway, and the step (b) includes the stepof advancing the filament through the passageway.
 32. A method fordelivering anesthesia into a tissue comprising the steps of. a.providing a quantity of filament; b. preloading the filament with atleast one liquid anesthetic agent; c. feeding an end of the filamentinto a hollow shaft having a tip; d. inserting the hollow shaft into aregion that includes at least a portion of the tissue; e. advancing thefilament along the shaft into the tissue.
 33. A method as in any one ofthe preceding claims, wherein the filament is a length of suture.
 34. Amethod as in any one of the preceding claims further comprising the stepof severing the filament such as to provide a desired length of filamentwithin the body of the subject.
 35. A method according to claim 34,wherein the step of severing the filament includes determining thedesired length of the filament during a clinical procedure.
 36. A methodfor delivering a stent into a vas of a body, the method comprising: a.preloading the stent into a shaft; b. inserting the shaft into the vas;c. advancing a filament along the shaft into the body so as to propelthe stent in advance of the filament; and d. retracting the filament.37. A method for modifying a tissue property of a subject, the methodcomprising: a. providing a quantity of suture material in particulateform; b. suspending the suture material in a liquid carrier to create asuture suspension; c. opening a portal in the body of the subject; andd. inserting the suture suspension through the portal into a region thatincludes at least a portion of the tissue.
 38. A method according toclaim 37, wherein the property includes at least one of the mass, bulk,orientation, rigidity, flexibility, springiness, and permeability of thetissue.
 39. A method for removing filament from a site in the bodycomprising: a. inserting a hollow shaft into the site; b. hooking thefilament with a hooked tool; c. withdrawing the filament via the hollowshaft.
 40. A device for inserting a filament having a diameter into asite in the body of a subject, the vice comprising: a. a conduit havingan axis, an interior wall, a distal end for inserting into the site, anda proximal end; and b. a feeding mechanism for supplying the filamentincrementally along the axis of the conduit so as to emerge from thedistal end into the site in a manner such that support is providedacross all lengths of the filament longer than three times the diameterof the filament.
 41. A device for inserting a filament having a diameterinto a site in the body of a subject, the vice comprising: a. a conduithaving an axis, an interior wall, a distal end for inserting into thesite, and a proximal end; b. an inner cannula having an inner diametercorresponding generally to the diameter of the filament; c. a mountingarrangement permitting axial movement of the inner cannula; and d. anactuator mechanism for urging the inner cannula in axial reciprocationconsisting of forward motion and retrograde motion with respect to themounting arrangement.
 42. A device according to claim 41, wherein theinner diameter of the inner cannula is approximately equal to thediameter of the filament.
 43. A device according to claim 41, whereinthe mounting arrangement includes an outer cannula disposed coaxiallywith and external to the inner cannula.
 44. A device according to claim41, wherein the feeding mechanism further comprises a gripper forgrasping the filament synchronously with forward motion of the innercannula.
 45. A device according to claim 41, wherein the feedingmechanism further comprises a second gripper acting out of phase withthe first gripper for retaining the filament during retrograde motion ofthe inner cannula.
 46. A device according to claim 41, wherein thefeeding mechanism further comprises a brake for retaining the filamentduring retrograde motion of the inner cannula.
 47. A device according toclaim 41, wherein the inner cannula comprises distinct distal andproximal segments.
 48. A device according to claim 41, furthercomprising a containment spring for retracting the distal segment of theinner cannula toward the proximal segment of the inner cannula duringretrograde motion of the distal segment of the inner cannula.
 49. Adevice according to claim 41, wherein the mounting arrangement includesa tip for penetrating body tissue.
 50. A device according to claim 41,wherein the mounting arrangement further comprises a window, disposedproximally to the tip of the mounting arrangement and having a distaledge, for feeding the filament into the site.
 51. A device according toclaim 41, wherein the device further comprises a rotation arrangementfor holding the mounting arrangement in a chosen azimuthal angle withrespect to the axis of the conduit.
 52. A device for inserting afilament having a diameter into a site in the body of a subject, thedevice comprising: a. a conduit having an axis, an interior wall, adistal end for inserting into the site, and a proximal end; b. aplurality of conveyor belts engaged against the filament; and c. atleast one pulley for moving the conveyor belts.
 53. A device forinserting a filament having a diameter into a site in the body of asubject, the device comprising: a. a conduit having an axis, an interiorwall, a distal end for inserting into the site, and a proximal end; b. atoothed wheel for advancing the filament; and c. an idler wheel forretaining the filament in contact with the toothed wheel.
 54. A devicefor inserting a filament having a diameter into a site in the body of asubject, the device comprising: a. a conduit having an axis, an interiorwall, a distal end for inserting into the site, and a proximal end; b. afirst and second strut for holding the filament against the wall of theconduit; c. a reciprocating shaft disposed along the wall of the conduithaving a head articulated downward from a bend in the shaft and achannel disposed proximally with respect to the head; d. a partial pivotdisposed across the conduit in a sense perpendicular to the axis of theconduit and distally with respect to the head of the shaft for forcingthe shaft head into engagement with the filament; and e. a mechanism fordriving the shaft in an advancing direction such that the filament isadvanced into the tissue until the channel of the reciprocating shaftaligns with the partial pivot, permitting it to spring back into itsoriginal shape and to disengage the filament.
 55. A device as in any oneof claims 40, 41, or 52-54 inclusive, wherein the conduit includes oneof a rigid, semi-rigid, and flexible tubular structure.
 56. A device asin any one of claims 40, 41, or 52-54 inclusive, further comprising: a.an inlet for receiving fluid; b. a channel for directing the flow offluid toward the site; and c. a fluid control for regulating theinjection of fluid into the channel.
 57. A device according to claim 56,wherein the channel is identical to the conduit inserted into the site.58. A device as in any one of claims 40, 41, or 52-54 inclusive, furthercomprising a storage arrangement for storing filament before it issupplied by the feeding mechanism.
 59. A device according to claim 58,wherein the storage arrangement is a spool.
 60. A device as in any oneof claims 40, 41, or 52-54 inclusive, further comprising a rewindmechanism for retracting filament from the site.
 61. A device as in anyone of claims as in any one of claims 40, 41, or 52-54 inclusive,further comprising a counter for tracking the length of filament whichhas been fed into the body site.
 62. A device as in any one of claims40, 41, or 52-54 inclusive, further comprising a filament cutter.
 63. Adevice according to claim 62, wherein the filament cutter comprises: a.a torquable head, disposed adjacent to the distal end of the conduit,having a rotation axis coincident with the axis of the conduit and anoff-axis window for passing the filament into the site in the body; b. ashearing surface disposed on at least one of the distal end of theconduit and the torquable head such that rotation of the torquable headsevers the filament; and c. a means for rotating the torquable headabout the rotation axis of the torquable head.
 64. A device according toclaim 63, wherein the means for rotating the torquable head is a torquewire disposed along the axis of the conduit.
 65. A device according toclaim 41, further comprising a filament cutter, the filament cuttercomprising: a. a stop disposed within the mounting arrangementproximally to the distal end of the mounting arrangement; and b. asharpened edge disposed on at least one of the inner cannula and thestop such that motion of the inner cannula against the stop causescutting of the filament.
 66. A device according to claim 50 furthercomprising a filament cutter having a mechanism for driving the innercannula past the distal edge of the window of the mounting arrangementin such a manner as to cause shearing of the filament.
 67. A deviceaccording to claim 40, 41, or 52-54 inclusive, further comprising amotor for repetitively cycling the feeding mechanism.
 68. A device forinserting a filament having a diameter into a site in the body of asubject, the device comprising: a. a conduit having an axis, an interiorwall, a distal end for inserting into the site, and a proximal end; andb. a feeding mechanism for supplying the filament along the axis of theconduit so as to emerge from the distal end; and c. a filament cutterfor shearing the filament.
 69. A device for inserting a filament havinga diameter into a site in the body of a subject, the device comprising:a. a conduit having an axis, an interior wall, a distal end forinserting into the site, and a proximal end; and b. a feeding mechanismfor supplying the filament continuously along the axis of the conduit soas to emerge from the distal end; and c. a filament cutter for shearingthe filament.
 70. A device for inserting a filament having a diameterinto a site in the body of a subject, the device comprising: a. aconduit having an axis, an interior wall, a distal end for insertinginto the site, and a proximal end; and b. a feeding mechanism forsupplying the filament incrementally along the axis of the conduit so asto emerge from the distal end; and c. a filament cutter for shearing thefilament.
 71. A device for removing a filament from a site in the bodyof a subject, the device comprising: a. a conduit having a distal endfor inserting into the site; and b. a hook for snagging and withdrawingthe filament through the conduit.